The so-called CAI (“Controlled Auto Ignition”) combustion process as Otto cycle operating mode of an internal combustion engine is merely possible in a limited operating range. For on the one hand the engine rotational speed range is limited upwards for the CAI combustion operation in that with engine rotational speeds which are too high pressure gradients which are too high and can damage the internal combustion engine can occur in the combustion chambers of said cylinder during the respective combustion process. On the other hand the high residual gas rates demanded for the CAI combustion operation in the combustion chambers of the cylinders of the internal combustion engine limit the cylinder charges with fresh air of said combustion engine and thus the engine rotational moment that can be achieved. The danger of delayed combustion or a combustion misfire in the respective cylinder due to low charge temperature and retarded combustion start in CAI combustion operation resulting from this furthermore limits its rotational speed operating range towards the bottom, so that as a rule no idle speed can be realized in the CAI combustion mode. If the prerequisites in terms of engine rotational speed, engine rotational moment, residual gas rate of combusted air/fuel mixture in the combustion chamber of the respective cylinder or other CAI typical parameter for the CAI operating mode of the Otto cycle combustion engine is not satisfied, said combustion engine in practice is externally ignited in the so-called SI (“Spark Ignition”) operating mode. In order to be able to bring the respective combustion engine in the CAI operating mode at all, starting from the SI combustion operation residual gas of combusted air/fuel mixture is retained in the combustion chamber of the respective cylinder during its exhaust cycle in that a changeover is performed more preferably through camshaft lift changeover to a smaller valve lift of the respective exhaust valve of this cylinder.
If the internal combustion engine is in the CAI operating mode and a pull fuel cut off is performed, i.e. the injection of fuel is switched off over the period of time of at least one combustion cycle, exclusively fresh air is pumped through the internal combustion engine. This means that hot residual gas, which is a prerequisite for initiating the CAI combustion is retained in the combustion chamber of the respective cylinder which happens to be in the exhaust stroke through camshaft lift changeover in conjunction with a—for example two-stage—valve lift changeover, is missing. Consequently reemployment in the fired combustion operation of the CAI combustion mode could not take place directly in the CAI mode but the detour via the externally ignited SI operating mode would be necessary. Such a change or such a changeover from CAI operating mode to the SI operating mode after a pull fuel cut off phase would be control-technically expensive, would pose change over risks and be inefficient. More preferably valuable CAI potential, i.e. the high combustion efficiency and low NOx emissions at the same time in accompanying the CAI operating mode would be lost.